The Respiratory System

1
The Respiratory System

• System Evolution
• Major Parts of the Respiratory System
• Functions of the Respiratory System

2
The Evolution of the Respiratory System

• Early creatures did not have a respiratory
  system but rather exchanged gasses through their
  skin. (Still true today as with planarians,
  hydra, and some amphibians) These animals
  usually have very large surface areas to maximize
  respiration.
• More Advanced and Evolved animals have developed
  systems that include lungs, trachea, bronchial
  tubes and other tissue structures that help with
  respiration

3
Simple to Complex Respiratory Systems
4
Breathing

• Diaphragm and Intercostal Muscles
• Separate the Thoracic Cavity from the Pelvic and
  Abdominal cavities.
• Diaphragm also expands and contracts leading to
  intake and expulsion of air from the lungs.

5
Breathing Cont.

• Diaphragm contracts? chest cavity expands?
  pressure goes down? air goes into lungs
• Diaphragm relaxes? chest cavity gets smaller?
  pressure goes up ? air goes out of lungs

6
Moving Air

• Nose- filters bacteria and dirt through tiny
  hairs and cilia
• Pharynx-Throat
• Mouth and nose come together
• Larynx- Voicebox
• Vocal Chords (ligaments that vibrate when air
  goes past)
• Adams Apple (larynx swells during puberty)
• Trachea-Windpipe goes to lungs
• Made of cartliage
• Cilia line the inside and make mucous
• Epiglottis- flap of tissue that closes over
  trachea when you swallow

7
Lungs

• Location of Gas Exchange
• Trachea to the Bronchi to Bronchioles to Alveoli
• Alveoli are tiny air sacs in lungs

8
How Blood Gets O2 Happy

• Deoxygenated blood flows into the heart form vena
  cava
• Right atrium and ventricle
• Then into the Pulmonary Artery
• Goes to lungs
• Gets oxygen
• Returns through pulmonary veins
• Goes to heart
• Left atrium and ventricle
• Rest of body

9
Diseases of the Mighty Lungs!

• Pneumonia
• Infection of the lungs where the lungs fill with
  pus and fluid (Sometimes the fluid becomes
  thicker, more like peanut butter than liquid.)
• Most forms caused by either a bacterium or a
  virus that infects the lungs.
• AIDS patients (With weakened immune systems) are
  subject to a very rare form (Rare in non-AIDS
  patients) caused by the protozoan Pneumocystis
  carinii.
• Affected parts of the lungs become non-functional
  as they fill with fluid.
• In some advanced cases, people must wear masks to
  avoid spraying pus and mucus on people around
  them.

10
Lung Cancer

• Lung Cancer follows related steps
• Thickening and Callusing of cells lining the
  bronchi. (Cells callus whenever cells are
  exposed to irritants.)
• Loss of Cilia in air way now impossible to
  filter dust and dirt from settling in the lungs.
• A tumor begins to develop.
• The tumor then grows until the bronchus is
  blocked, cutting off air supply to the affected
  lung.
• Then, the lung collapses and and the secretions
  in the lung spaces become infected and pneumonia
  or localized areas or pus result.

Normal
Cancer